implement dynamic dropdown

[katherinemwong]

what it does:

• add experiment, sample, cells into the input text box
• after adding sample to database, will show list of previously submitted fastq experiments, sample, and cells

what it does not do:

• show unique experiment, sample, cells
• create a dynamic dropdown before submitting sample

[katherinemwong]

#33

[katherinemwong]

#28

[byee4]

To make things unique:

say you have a list 

mylist = [1, 2, 3, 3, 3]
mylist = list(set(mylist))
> [1,2,3]